c220 CDi losing water

[Merc Driver C220 CDi]

I own a C220 Cdi 2012 85k, Recently the coolant top up message appears around every 4 weeks or there abouts I top up the coolant maybe around 3/4 of a cup and all is ok for around the 4 week mark and it comes on again.

i haven't had chance to have a good look for leaks etc and there are no noticable signs of water leakage but I have noticed what looks like water marks spottles around the expansion bottle as if the cap maybe leaking perhaps under pressure ?

Are there any noted problems or does anyone else have or had similar issues ?

Starts drives as it always has, fuel consumption the same no over heating issues so not too worries that it maybe something sinister

any ideas ?

 

[John Laidlaw]

when was the coolant last changed do you know?

 

[Merc Driver C220 CDi]

A Couple of years ago aprox

 

[onefortheroad]

Try a new cap maybe ?

 

[Gazwould]

3 wrong answers , tut , tut , lol .

Mercedes redesigned two water feature parts .


From plastic to metal .




And from two to three .

 

[Dean Fletcher]

In my experience it will be either 2 things. Either the water pump or fuel filter housing. Fingers crossed for the latter easy fix and cheaper.

 

[Dean Fletcher]

3 wrong answers , tut , tut , lol .

Mercedes redesigned two water feature parts .


From plastic to metal .

View attachment 64828


And from two to three .

View attachment 64829

View attachment 64830

My car didn't have a place for the extra 3rd bolt on the filter housing.

 

[Merc Driver C220 CDi]

Any other symptoms I should look out for other than losing water ?

 

[Dean Fletcher]

Any other symptoms I should look out for other than losing water ?

Get a light and have a look down the fuel filter area you will see liquid if its the housing

 

[Dean Fletcher]

It will look like this.

 

[onefortheroad]

3 wrong answers , tut , tut , lol .

Mercedes redesigned two water feature parts .


From plastic to metal .

View attachment 64828


And from two to three .

View attachment 64829

View attachment 64830

Mine was a guess , hence the ? . .

 

[John Laidlaw]

Mine was a guess , hence the ? . .

And mine wasn't an answer, given the "when" at the beginning which usually denotes a question, as opposed to a statement along the lines of " 3 wrong answers. Tut,Tut,Lol"....

 

[mioba]

well the OP knows where to look.

 

[onefortheroad]

And mine wasn't an answer, given the "when" at the beginning which usually denotes a question, as opposed to a statement along the lines of " 3 wrong answers. Tut,Tut,Lol"....

Still not sure where the 3rd answer come from tbh .. lol

 

[ajlsl600]

Redesigned pts..am I to assume that plastic pump no longer fitted to new motors or ? U guys know wot a cynic I am...
Try cap.

 

[Steve@Avantgarde]

Thermostat housing also leak on these.

 

[mioba]

plastic housing cycling hot and cold always fails.
What a stupid design all in the quest for cheapness and lightness.
beggers belief